Abstract
Older adults with mild cognitive impairment (MCI) manifest impaired explicit memory. However, studies on implicit memory such as repetition effects in persons with MCI have been limited. In the present study, 17 MCI patients and 16 healthy normal controls (NC) completed a modified delayed-match-to-sample task while undergoing functional magnetic resonance imaging. We aim to examine the neural basis of repetition; specifically, to elucidate whether and how repetition-related brain responses are altered in participants with MCI. When repeatedly rejecting distracters, both NC and MCI showed similar behavioral repetition effects; however, in both whole-brain and region-of-interest analyses of functional data, persons with MCI showed reduced repetition-driven suppression in the middle occipital and middle frontal gyrus. Further, individual difference analysis found that activation in the left middle occipital gyrus was positively correlated with rejecting reaction time and negatively correlated with accuracy rate, suggesting a predictor of repetition behavioral performance. These findings provide new evidence to support the view that neural mechanisms of repetition effect are altered in MCI who manifests compensatory repetition-related brain activities along with their neuropathology.
Original language | English |
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Pages (from-to) | 693-704 |
Number of pages | 12 |
Journal | Journal of Alzheimer's Disease |
Volume | 53 |
Issue number | 2 |
DOIs | |
State | Published - 2016 |
Bibliographical note
Funding Information:This work was supported by the National Natural Science Foundation of China (31470998, 31271108, 31200847, and 31300856), National Science and Technology Pillar Program of China (2009BAI77B03), CAS/SAFEA International Partnership Program for Creative Research Team (Y2CX131003), Scientific Foundation of Institute of Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences (KLMH2014ZK02), and by United States NIH grants National Institute of Aging (AG000986, T32 AG000242, P30AG028383, and UL1TR000117). We thank C. Guo for his contribution in the current version of the task design
Publisher Copyright:
© 2016 - IOS Press and the authors. All rights reserved.
Keywords
- Delayed-match-to-sample task
- Functional MRI
- Mild cognitive impairment
- Repetition
- Repetition suppression
ASJC Scopus subject areas
- Neuroscience (all)
- Clinical Psychology
- Geriatrics and Gerontology
- Psychiatry and Mental health